Composition having a low freezing-point.



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GEORGE E. FERGUSON, OF NEW YORK, N. Y., ASSIGNOR T0 PYRENE MANUFACTURING COMPANY, A. CORPORATION OF DELAWARE.

COMPOSITION HAVING A. LOW FREEZING-POINT.

No Drawing.

To all whom it may concern Be it known that I, GEORGE E. Fnncuson, a citizen of the United States, and resident of the city, county, and State of New York,

have invented certain new and useful Improvements 1n Compositions Havlng a Low F reezing-Point, of which the following is ing point than that of the carbon tetrachlorid a specification.

The object of'this invention is to produce a compound or solution having a low freezing point, or more specifically,-to lower the normal freezing point of the solvent of the compound. Carbon tetrachlorid has been selected as illustrative of a solvent which, being a solvent for many other compounds, is useful for many purposes, among which fire extinguishing compounds may be mentioned, carbon tetrachlorid being noninflammable.

The extensive uses to which carbon tetrachlorid is put, make it desirable to lower its normal freezing point (which in the chemically pure state is -19.5 C.) to permit its use in temperatures where extreme cold weather prevails that it may be utilized as a liquid and at the same time maintain all of its useful properties.

With this in mind, l have performed a large number of experiments to ascertain if some underlying principle can be found to govern this depression of the freezing point.

It is a Well known fact that, considering inorganic compounds and inorganic solvents, the depression of the freezing point depends upon thesolubility of the salts used and the degree of dissociation which takes place when these salts are dissolved in the solvent (which solvent in most cases, is water),

The laws governing the depression of the freezing point for electrolytes are simple:

1. The freezing point of a solution is lower than that of the pure solvent.

2. The depression of the freezing point is proportional to the concentration of the solution.

3. llf t degrees-be the depression produced by the presence ofp grams of substance in 100 grams of the solvent, then the molecular depression P (where m is the molecular weight of the dissolved substance).

Specification of Letters Patent.

Application filed October 20, 1914. Serial No. 867,579.

in the solution of a compound like "a'zo benzene (C H N C H which is very soluble in carbon tetrachlorid. When this substance is added the result is a higher freez alone, and the more azo' compound dissolved the higher the freezing point.

When a number of such experiments were tried and no principle could be established, it was decided to try out all the commercially possible substances which could be dissolved in carbon tetrachlorid, to ascertain which would depress the freezing point. It was found that among the great variety of compounds tried out about 150 accomplished the desired result.

It is understood that some of these compounds would prove detrimental to the use of carbon tetrachlorid under certain conditions while they might prove very acceptable under others.

To simplify the list, it was thought best to classify these substances under different chemical groups, such as, (.1) esters and ethers; (2) amins and amino compounds; (3) aldehydes and ketones; (4) alcohols; (5) oils; (6) hydrocarbons, substitutes and derivatives; (7) phenols and phenol derivatives; (8) terpenes, camphors and (9) acids, etc.

About the only generality which can be made in regard to all this investigation is the fact that most compounds which are in the liquid state at normal (room) temperatures and which are soluble in carbon tetrachlorid lower the freezing point of the carbon tetrachlorid and vice versa, most of the compounds which are solid at normal temperature and soluble in carbon tetrachlorid do not lower the freezing point but in most cases raise it. There are, however, enough exceptions to this generality to render it impossible of a rule. a

In this investigation no attempt was made to determine the quantity of substance dissolved in a known amount of solvent to general application as produce an observed depression of the freezsible Among the ethers which I have found suitable for lowering the freezing point of carbon tetrachlorid may be mentioned anisol and phenetol.

It is obvious that it is impossible to cover every compound, in the manner described, to ascertain if the freezing point of carbon tetrachlorid could be lowered by dissolving the compound therein; I have however, made tests in each class of compounds with commercially possible examples in each class. What future developments may be made toward the reduction of the cost of a number of the expensive compounds,- thus ,rendering the same commercially possible, is problematical but my experiments and tests show that it is posto V generalize in these different classes or divisions. For example, I found that every ether which was liquid at normal or room temperature would lowerthe freezing point of carbon tetrachlorid. (This statement is based on my tests of forty-five different compounds of this class which were soluble in carbon tetrachlorid).

Four hundred and thirty experiments were performed; the substances selected being taken from the chemical catalogues. All of the organic substances costing one dollar or less per ounce were triedas it was considered that these compounds, from the standpoint of cost, would be commercially possible. It was found that a great many of these compounds were insoluble in carbon tetrachlorid and therefore eliminated themselves from the investigation.

What-I claim is:

A solution having a low freezing point comp ising carbon tetrachlorid and anisol disso ved therein.

Signed at the city, county and State of New York, this 8th day of October, 1914.

GEORGE E. FERGUSON. Witnesses:

HAROLD W. CHAPMAN, LEWIS J. DOOLITTLE. 

